326 



INJURIOUS AND BENEFICIAL INSECTS OK CALIFORNIA. 



are exposed above ground. The larva' eat through the tender scales to 

 the heart, where they feed and remain during the winter. There is 

 but one brood a year. 



Nature of Work. — The maggots usually feed in the center of the 

 bulbs, and their presence is often quite difficult to detect. One method 

 is to squeeze the bulbs near the neck when they are dug, and if they 

 give to the pressure of the hand they are almost certain to be hollowed 

 out by the maggots. When cut open the bulbs appear as represented 

 in Fig. 319. There is usually but one maggot in a bulb, but occasionally 

 two or three may be found in one plant. In some localities the insect 

 often proves very serious and causes great loss to bulb growers. 



Distribution. — The maggots of Ihis fly have often been taken in 

 quarantine in shipments of bulbs from Europe. The insect has become 

 established in the San Francisco Bay region and has been taken in 



Marin, Alameda and Santa Cruz coun- 

 ties. It is also abundant and quite 

 destructive in British Columbia, in the 

 vicinity of Vancouver. 231 ' 



Food Plants. — The following lily 

 bulbs are known to be hosts of the fly : 

 Amaryllis, daffodil, Euryclcs, Gal- 

 tonia, Jlippeastrum, hyacinth (culti- 

 vated and wild), Narcissus, Saltonia, 

 Scitta it til Oris, tulip (rarely) and 

 Vallota. 



Control. — Control measures, though 

 affording only partial relief, are well 

 worth observing, as they often give 

 very satisfactory results. If bulbs do 

 not grow in the spring they should 

 be dug and destroyed, as well as all 

 unhealthy looking plants. All should 

 be dug in the summer and carefully 

 sorted to eliminate those infested. 

 Bulbs may be steeped from twenty- 

 four to forty-eight hours in lukewarm water, care being taken to see 

 that the water does not get cold and the bulbs become chilled. Prac- 

 tically all of the larva* may be drowned in this way. After soaking, the 

 bulbs should be carefully dried. Capturing adults early in the spring 

 with a net is also recommended. No infested bulbs should ever be 

 planted. 



Fig. 320. — Adult narcissus bulb-flv, 

 Merodon equestris Fab. Enlarged three 

 times. (After Childs, Mo. Bui. Cal. 

 Hort. Com.) 



3 »Treheme, R. C, Proe. Ent. Soe. Brit. Columbia, No. 4, n. s., pp. 31-32, 1914. 



